/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.service;

import java.util.Properties;

import cgl.narada.event.NBEvent;


/** This class provides a set of core functions that service implementations
    need to satisfy. All services within the system need to conform to this
    interface. 

    @author Shrideep Pallickara
    $Date$
    $Revision$
*/

public interface Service {
  /** Load the service based on  the specified properties. */
  public void loadService(Properties serviceProperties) 
    throws ServiceException;
  
  /** Start the service. Throws a ServiceException, in the event that there
      are problems with starting the service */
  public void startService() throws ServiceException;
  
  /** Stop the service */
  public void stopService() throws ServiceException;
  
  /** Return true if the service is started and is running. */
  public boolean isStarted();
  
  /** Returns false if the service is stopped */
  public boolean isStopped();
  
  /** Returns a description of the service */
  public String getServiceDescription();
  
  /** A service exception listener allows a client to be notified of a problem
      asynchronously*/
  public void 
  registerServiceExceptionListener(ServiceExceptionListener listener,
				   String listenerId)
    throws ServiceException;


  /** Deregisters a previously registered service exception listener */
  public void deregisterServiceExceptionListener(String listenerId)
    throws ServiceException;
  
  /** A service notification listener allows a client to be notified of a 
      service related diagnostic information asynchronously*/
  public void
  registerServiceNotificationListener(ServiceNotificationListener listener,
				      String listenerId)
    throws ServiceException;
  
  /** De registers a previously registered service notification listener */
  public void
  deregisterServiceNotificationListener(String listenerId)
    throws ServiceException;

  
  /** Gets a list of the different types of events handled by the service */
  public int[] getEventTypesHandled();
  
  /** This is an event invoked to handle processing for a given event */
  public void handleEvent(NBEvent nbEvent) throws ServiceException;
  
  /** Gets a list of the services performed by this service */
  public int[] getServicesPerformed();
  
  
  /** Performs a service request by a service. */
  public void performService(NBEvent nbEvent, int serviceType, 
			     Service requestingService) 
    throws ServiceException; 
  
  /** This is the method called upon the completion of a previously requested
      service. In the case that the service could not be performed for any
      reason, the status indicates this with the service exception providing
      a reason why. */
  public void servicePerformed(NBEvent nbEvent, boolean status, 
			       ServiceException serviceException);

}
